The vehicle seat backrest may in particular be a rear backrest or a backrest of a backward-facing seat, which in particular is fastened directly to the vehicle structure. The divided vehicle seat backrest has a first and a second backrest part which are foldable independently from one another. The division may in particular be uneven, for example 60-40, or also even. In their upper region or area the backrest parts are preferably also laterally lockable together on the outside and on the inside, for example.
The backrest parts are each rotatably and/or pivotably supported on the left and right, for example, in bearing pins; thus, the left backrest part is mounted on its left side in an outer bracket, and correspondingly the right backrest part is mounted on its right side in an outer bracket. Toward the middle, the two backrest parts are rotatably mounted on a center bracket (middle receptacle).
A high degree of collision safety must be ensured in the connection of the backrest parts to the center bracket; in a typical collision the backrest parts may in particular be pulled outwardly, or pivoted outwardly and upwardly at their inner bearing points. Therefore, securing elements and additional components for a hold that is secure in the event of a collision are generally provided.
It is known from DE 299 23 174 U1 to use a shared bearing pin for supporting both backrest parts on the center bracket. The bearing pin is placed in the axial direction through a first backrest part, the center bracket, and a second backrest part. In addition, a securing element is placed between the center bracket and one backrest part, the securing element having a recess which has a broader and a narrower region or area and which may be adjusted perpendicular to the pivot axis in order to enclose the bearing pin with the narrower area for securing. The center bracket is formed by two bearing blocks, between which the securing element is inserted. In addition, an intermediate sleeve which is used as a spacer and a positive fit means is placed between a bearing block and a backrest part. A tapered securing region or area having a securing shoulder which represents the end is formed at the end of the bearing pin, and is intended to prevent the bearing bore of the one backrest part from slipping from the bearing journal, even under extreme load; however, these areas are not relevant for normal operation.
DE 296 20 145 U1 discloses a divided motor vehicle rear seat backrest having a more complex connection of the backrest parts to the center bracket; the connection to the outer bracket is established by outwardly protruding bearing pins having spring tongues which are radially outwardly spreadable to prevent them from being pulled out.
Thus, these types of vehicle seats generally have a complex design with a plurality of supplementary parts and securing means, and require complicated manufacture with many assembly steps.